title: Characterization of single α-tracks by photoresist detection and AFM analysis-focus on biomedical science and technology.
abstract: The interactions between energetic ions and biological and/or organic target materials have recently attracted theoretical and experimental attention, due to their implications for detector and device technologies, and for therapeutic applications. Most of the attention has focused on detection of the primary ionization tracks, and their effects, while recoil target atom tracks remain largely unexplored. Detection of tracks by a negative tone photoresist (SU-8), followed by standard development, in combination with analysis by atomic force microscopy, shows that both primary and recoil tracks are revealed as conical spikes, and can be characterized at high spatial resolution. The methodology has the potential to provide detailed information about single impact events, which may lead to more effective and informative detector technologies and advanced therapeutic procedures. In comparison with current characterization methods the advantageous features include: greater spatial resolution by an order of magnitude (20 nm); detection of single primary and associated recoil tracks; increased range of fluence (to 2.5 × 10(9) cm(-2)); sensitivity to impacts at grazing angle incidence; and better definition of the lateral interaction volume in target materials.
authors.affiliation: Department of Oncology, University of Oxford, MRC/CRUK Gray Institute for Radiation Oncology and Biology, Oxford, UK. Department of Biomedical Science, Tshwane University of Technology, Pretoria, South Africa.
authors.forename: Nadia
authors.initials: N
authors.lastname: Falzone
authors.forename: Sverre
authors.initials: S
authors.lastname: Myhra
authors.forename: Radka
authors.initials: R
authors.lastname: Chakalova
authors.forename: Mark A
authors.initials: MA
authors.lastname: Hill
authors.forename: James
authors.initials: J
authors.lastname: Thomson
authors.forename: Katherine A
authors.initials: KA
authors.lastname: Vallis
mesh_terms: D000512:Alpha Particles; D004852:Epoxy Compounds; D018625:Microscopy, Atomic Force; D011108:Polymers; D011853:Radiobiology / Q000379:methods*; D011874:Radiometry; D015203:Reproducibility of Results
chemical_list: D004852:Epoxy Compounds; D011108:Polymers; C520895:SU-8 compound